1. Field of the Invention
The present invention relates to a foolproof structure for an interface module, and more particularly to a foolproof structure that prevents a PCI Express (PCI-E) interface from being connected incorrectly and assures the PCI-E interface to be connected to a correction position.
2. Description of the Related Art
PCI Express (PCI-E) was originally developed by Intel and is considered as a new wideband I/O interface that can replace the PCI. The most significant improvement made by the PCI Express resides on its node-to-node topology that allows inverters to share the resources (such as the bus bandwidth) for the connected PCI Express devices according to their priorities. Each of the devices can be accessed or connected to the inverter directly and independently. Further, the inverter processes the transmitted data in the first priority, so that instant application programs can access the inverters immediately.
Another improvement over the PCI resides on the higher bandwidth of the PCI Express. A single channel can transmit 250 MB of data per second in a one-way transmission (and 500 MB per second for the two-way transmission), and the present PCI Express provides five formats (x1, x2, x3, x4 and x16) for the use of different bandwidths. The PCI Express (x2) comprises two channels, and the maximum one-way and two-way bandwidths are 500 MB per second and 1000 MB per second respectively.
Due to the compatibility issue of the PCI-E specification and electronic signals, the left and right sides of the modules are not compatible, and thus the I/O modules cannot be drawn out if they are installed improperly. Therefore, users have to remember which side of the module should be inserted before electronic signals can be connected properly. Further, a module cannot be inserted into the insert slot of a motherboard with a different specification. For instance, a module with a PCI-E (x4) specification should not be inserted into a motherboard with a PCI-E (x8) specification, or else the PCI-E specification and electronic signals will be incompatible, and improper operations or damages to the I/O module may result.